Conveyor axle for a traveling grate

ABSTRACT

The invention concerns a conveyor axle for a traveling grate and wherein the axle is cooled on the inside by a circulating coolant and is supported at both ends.

United States Patent 1191 Korting et al.

[ 1 Mar. 11, 1975 CONVEYOR AXLE FOR A TRAVELING GRATE Inventors: Reinhard Korting; Alois Kliiger,

both of Neubeckum, Germany Assignee: Polysius AG, Neubeckum, Germany Filed: Aug. 31, 1973 Appl. No.: 393,649.

Foreign Application Priority Data- Dec. 5, 1972 Germany 7244486 U.S. Cl 165/89 110/40 D, 432/236,

432/246 1m. Cl c210 9/00 Field of Search 110/40 A, 40 R, 40 C, 40 E; 432/246, 60, 235, 244, 236; 165/89 [56] References Cited UNITED STATES PATENTS 1,536,832 5/1925 Evans 165/89 3,100,631 8/1963 Schmidt 165/89 3,406,748 10/1968 Jarreby 165/89 Primary ExaminerKenneth W. Sprague Assistant Examiner-James C. Yeung Attorney, Agent, or Firm-Learman & McCu110ch [57] ABSTRACT The invention concerns a conveyor axle for a traveling grate and wherein the axle is cooled on the inside by a circulating coolant and is supported at both ends.

3 Claims, 2 Drawing Figures CONVEYOR AXLE FOR A TRAVELING GRATE The chain members of traveling grates are generally braced by supporting rollers fitted to rotatable conveyor axles. Because of the great thermal stress to which traveling grates are frequently subjected, it is necessary to cool the conveyor axles.

One prior art conveyor axle is manufactured hollow for cooling purposes; the coolant (generally cooled air) is introduced into the one end of the axle and discharged at the other axle end. That construction has various disadvantages.

Since for reasons of costs the cross section of the conveyor axle is kept as small as possible at the location of the bearing, only a passage of comparatively small cross section is available for directing the coolant through the one axle end, thus limiting the amount of the coolant. The cooling effect achieved by known construction types is furthermore also comparatively small, because a large portion of the coolant flows through the conveyor axle without coming in close contact with the wall of the coneyor axle which is to be cooled.

A further disadvantage of conventional constructions is the fact that longitudinally the conveyor axle is cooled quite unevenly. The area cooled most is the end of the conveyor axle through which cooled air is supplied; the cooling effect is already considerably less (as a result of the higher temperature of the coolant) in the middle portion of the conveyor axle, which portion is generally subjected most strongly to thermal and mechanical wear. Finally, cooled most insufficiently is the bearing located at the other axle end through which the cooling airis discharged.

An object of the present invention is to overcome the aforementioned deficiencies of conventional constructions by the provision of a conveyor axle characterized by a particularly intense cooling especially of middle portion of the axle which is subjected to the highest temperature.

In accordance with the invention, the interior of the conveyor axle is divided into two centrally disposed conduits extending from the two axle ends and two outer cooling passages annularly positioned about the conduits, joining up with the conduits approximately at the center and discharging near the axle ends.

Such embodiment utilizes both axle ends for introducing the coolant. The invention thus utilizes the teaching that the coolant need not necessarily be discharged from a central location, but may also be discharged at the periphery of the conveyor axle when cooling air is used which is released into the atmosphere. This approach makes it possible to approximately double the conduit cross section, thus considerably increasing the amount of coolant used.

According to the invention, the coolant is introduced to the middle portion of the axle from both sides, by means of the centrally disposed conduits and can produce a particularly intensive cooling effect there, since it is still cold for the most part. This ensures that the conveyor axle is sufficiently cooled at its middle section, where it is subject to the greatest thermal and mechanical stresses. The flow of the coolant in a direction symmetric to the center of the axle, has the further effect of evenly and intensively cooling both bearings provided at the axle ends.

A further advantage of the invention ultimately consists in the fact that desirable counter current cooling takes place between the still cold coolant drawn through the central conduit and the coolant flowing through the outer cooling passage, which has been warmed as a result of its flow through the conveyor axle, during which it comes in contact with-the warm axle wall. Since the coolant for the conveyor axle of the invention is forced to flow in the outer cooling passage in direct vicinity of the warm conveyor axle wall, an extremely intensive cooling is effected.

Two embodiments of the invention are illustrated in the drawings, wherein:

FIG. 1 is a longitudinal sectional view of an axle according to one embodiment of the invention; and

FIG. 2 is a fragmentary sectional view of a second embodiment.

FIG. 1 discloses a conveyor axle for a traveling grate and having an outer wall 1 which is supported at both axle ends by bearings 2 and 2'. The interior of the wall 1 is divided by a separating wall 3 at approximately its middle.

The two halves of the axle contain a centrally disposed conduit 4, 4' concentric with the wall 1 but of smaller diameter so as to form an outer cooling passage 5, 5'. The central conduits 4, 4' and the outer cooling passages 5, 5 are separated from each other by tubes 6, 6' ending shortly before separating wall 3.

The two centrally disposed conduits 4,4 extend from the two axle ends 7 and 7 which are hollow to provide inlets in communication with the conduits 4, 4. The outer cooling passages 5, 5', which are annularly positioned about central conduits 4, 4, communicate with the central conduits 4, 4 at about the middle of the axle and have discharge openings 8, 8 close to the axle ends, for example, at the periphery of the conveyor axle. The cross section of the outer cooling passages 5, 5 is considerably smaller than the cross section of the central conduits 4, 4'.

The coolant, particularly cooled air, is supplied to both axle ends 7, 7 and thence through central conduits 4, 4' to the middle of the axle (arrows 9, 9 After deflection by the wall 3, the coolant then flows through the outer cooling passage 5, 5 (arrows l0, 10) thereby intensively cooling the wall of the conveyor axle as it returns in the direction toward the axle as it returns in the direction toward the axle ends, and the coolant is then discharged throughopenings 8, 8'.

Whereas in the emboidment of FIG. 1 each of the centrally disposed conduits 4, 4 is connected to the outer cooling passage 5, 5' located in the same half of the axle, FIG. 2 illustrates a variant, according to which each of the two central'conduits 14, 14 respectivelyis connected with the outer cooling passage 15 and 15 located in the opposite half of the axle. For this purpose, the outer cooling passages 15, 15 are constructed at their connection to the central conduits initially as segments only in the cross section; however, after this transitional zone they expand to a full annular cross section.

The embodiment of FIG. 2 incorporates a connection of the central conduits with the respective outer cooling passages that is'of somewhat more complex construction. However, this avoids diverting the coolant by within the area of the center of the axle, as is required by the embodiment of FIG. 1.

What is claimed is:

1. A conveyor axle for a traveling grate, said axle having an outer wall, a first conduit within said wall extending inwardly of said axle from one end thereof and being spaced from said wall to form a first passage surrounding said first conduit; a second conduit within said wall extending inwardly of said axle from its other end and being spaced from said wall to form a second passage surrounding said se ond conduit, said axle having inlet openings at its ends in communication with the respective conduits for supplying the latter with coolant, said passages being in communication with discharge openings at the ends of said axle for discharging coolant from the respective passages, said first conduit being in communication with said second passage and discharge openings are in said outerwall. 

1. A conveyor axle for a traveling grate, said axle having an outer wall, a first conduit within said wall extending inwardly of said axle from one end thereof and being spaced from said wall to form a first passage surrounding said first conduit; a second conduit within said wall extending inwardly of said axle from its other end and being spaced from said wall to form a second passage surrounding said second conduit, said axle having inlet openings at its ends in communication with the respective conduits for supplying the latter with coolant, said passages being in communication with discharge openings at the ends of said axle for discharging coolant from the respective passages, said first conduit being in communication with said second passage and said second conduit being in communication with said first passage whereby coolant introduced to the first and second conduits passes to the second and first passages, respectively.
 1. A conveyor axle for a traveling grate, said axle having an outer wall, a first conduit within said wall extending inwardly of said axle from one end thereof and being spaced from said wall to form a first passage surrounding said first conduit; a second conduit within said wall extending inwardly of said axle from its other end and being spaced from said wall to form a second passage surrounding said second conduit, said axle having inlet openings at its ends in communication with the respective conduits for supplying the latter with coolant, said passages being in communication with discharge openings at the ends of said axle for discharging coolant from the respective passages, said first conduit being in communication with said second passage and said second conduit being in communication with said first passage whereby coolant introduced to the first and second conduits passes to the second and first passages, respectively.
 2. A conveyor axle according to claim 1 wherein said first and second conduits communicate with the respective second and first passages at substantially the center of said axle. 